This is a prospective study of HIV infection, with the aims of investigating behavioral, clinical and immunological events surrounding seroconversion of HIV type-1. It will also determine standardized mortality ratios (SMRs) by cause among HIV-infected and uninfected IVDU's and investigate risk factors for significantly elevated causes of death via case-control studies. The lab was used for the following: DNA isolation, blood separation, ELISA, DNA sequencing, PCR and RNA isolation.